Improvisation is defined as the ability to perform an activity that was not prepared, that is to say it is developed in the spot.
Explanation:
Jazz is one of the genres that has been really recognized in the world of music due to the use of improvisation, there are some other genres such as rock, blues among others that also improvise but it is normally using simple chord progressions, while Jazz is characterized by its complexity and chord changes as well as altered chords, extended chords among other progressions.